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    <title>Document</title>

    
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<body>
    
    <h3>this</h3>
    <button id="btn">click me</button>


    <script type="text/javascript">

        function Person(color){
            console.log('this,',this)
            this.getColor=function(){
                console.log(' getColorthis,',this)
            }
        }

        window.document.getElementById('btn').onclick=Person('red')

        let p=new  Person('black')
        p.getColor()
      
    </script>
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